generateForAnnotatedElement method

  1. @override
Future<String?> generateForAnnotatedElement(
  1. Element element,
  2. ConstantReader annotation,
  3. BuildStep buildStep
)

Implement to return source code to generate for element.

This method is invoked based on finding elements annotated with an instance of T. The annotation is provided as a ConstantReader.

Supported return values include a single String or multiple String instances within an Iterable or Stream. It is also valid to return a Future of String, Iterable, or Stream.

Implementations should return null when no content is generated. Empty or whitespace-only String instances are also ignored.

Implementation

@override
Future<String?> generateForAnnotatedElement(
    Element element, ConstantReader annotation, BuildStep buildStep) async {
  if (element is! ClassElement) {
    throw 'Only classes can be annotated with @ORM().';
  }

  var generateMigrations =
      annotation.peek('generateMigrations')?.boolValue ?? true;

  if (!generateMigrations) {
    return null;
  }

  var resolver = buildStep.resolver;
  var ctx = await buildOrmContext({}, element, annotation, buildStep,
      resolver, autoSnakeCaseNames != false);

  if (ctx == null) {
    throw 'Invalid ORM build context';
  }

  // Create `FooMigration` class
  var lib = generateMigrationLibrary(ctx, element, resolver, buildStep);

  //if (lib == null) return null;
  return DartFormatter()
      .format(lib.accept(DartEmitter(useNullSafetySyntax: true)).toString());
}